分页

分页show.jsp

<%--
分页操作
<a href="serlect_all?pageindex=${pu.present_page_num>1?pu.present_page_num-1:1}">上一页</a>
<c:forEach var="i" begin="1" end="${pu.total_page_num}">

    <a href="serlect_all?pageindex=${i}">${i}</a>

</c:forEach>
<a href="serlect_all?pageindex=${pu.present_page_num+1}">下一页</a>
--%>

pageUtils

package com.zym.utils;

public class pageUtils {
    private int total_page_num;
    private int present_page_num;
    private int num_of_onepage;
    private int total_num;


    public int getTotal_num() {
        return total_num;
    }

    public void setTotal_num(int total_num) {
        this.total_num = total_num;
    }

    public pageUtils() {
    }

    public pageUtils(int total_page_num, int present_page_num, int num_of_onepage, int total_num) {
        this.total_page_num = total_page_num;
        this.present_page_num = present_page_num;
        this.num_of_onepage = num_of_onepage;
        this.total_num = total_num;
    }

    public int getTotal_page_num() {
        System.out.println(total_page_num+"=================");
        return total_page_num;
    }

    public void setTotal_page_num(int total_page_num) {
        this.total_page_num = total_page_num;
    }

    public int getPresent_page_num() {
        return present_page_num;
    }

    public void setPresent_page_num(int present_page_num) {
        this.present_page_num = present_page_num;
    }

    public int getNum_of_onepage() {
        return num_of_onepage;
    }

    public void setNum_of_onepage(int num_of_onepage) {
        this.num_of_onepage = num_of_onepage;
    }

    @Override
    public String toString() {
        return "pageUtils{" +
                "total_page_num=" + total_page_num +
                ", present_page_num=" + present_page_num +
                ", num_of_onepage=" + num_of_onepage +
                '}';
    }

//    public





}

UserDao

    public  List<User> SelectAll(pageUtils pu) throws SQLException, ClassNotFoundException {
        List<User> users = new ArrayList<>();
        conn = jdbcUtils.get_conn();
         pstt = conn.prepareStatement("select * from user limit ?,? ");
//         pstt = conn.prepareStatement("show tables ");
//        pstt.set;
        pstt.setInt(1,((pu.getPresent_page_num()-1)*pu.getNum_of_onepage()));
        pstt.setInt(2, pu.getNum_of_onepage());

        rs = pstt.executeQuery();
         User u =null;
         while (rs.next()){
             u = new User(rs.getInt("id"),rs.getString("name"),rs.getInt("age"));
             users.add(u);
         }

         jdbcUtils.close_all(conn,pstt,rs);
        return users;
    }

servlet

 try {
            UserDao userDao = new UserDao();



            //总页数
            //总条数
            //当前页数
            //一页有多少条

            //总条数
            int total_num = userDao.select_count();
            System.out.println("总条数"+total_num);

            //总页数
            int total_page_num = 2;

            //当前页数默认为1

            int present_page_num =1;
            if (request.getParameter("pageindex")!=null) {
                present_page_num=Integer.parseInt(request.getParameter("pageindex"));
                System.out.println(present_page_num+"1111111");
            }

            //一页有多少条
            int num_of_onepage = total_num/total_page_num;

            pageUtils pageUtils_obj = new pageUtils(total_page_num,present_page_num,num_of_onepage,total_num);
            System.out.println(pageUtils_obj.getTotal_page_num()+"---------------");
            request.setAttribute("pu", pageUtils_obj);

            List<User> users = userDao.SelectAll(pageUtils_obj);
//            boolean res = new UserDao().crete_table();
//            System.out.println(res+"=======================");
            request.setAttribute("users",users );



        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        request.getRequestDispatcher("show.jsp").forward(request,response);


//    }